Objects/iterobject.c

   1 /* Iterator objects */
   2
   3 #include "Python.h"
   4
   5 typedef struct {
   6         PyObject_HEAD
   7         long      it_index;
   8         PyObject *it_seq;
   9 } seqiterobject;
  10
  11 PyObject *
  12 PySeqIter_New(PyObject *seq)
  13 {
  14         seqiterobject *it;
  15         it = PyObject_NEW(seqiterobject, &PySeqIter_Type);
  16         if (it == NULL)
  17                 return NULL;
  18         it->it_index = 0;
  19         Py_INCREF(seq);
  20         it->it_seq = seq;
  21         return (PyObject *)it;
  22 }
  23 static void
  24 iter_dealloc(seqiterobject *it)
  25 {
  26         Py_DECREF(it->it_seq);
  27         PyObject_DEL(it);
  28 }
  29
  30 static int
  31 iter_traverse(seqiterobject *it, visitproc visit, void *arg)
  32 {
  33         return visit(it->it_seq, arg);
  34 }
  35
  36 static PyObject *
  37 iter_next(seqiterobject *it)
  38 {
  39         PyObject *seq = it->it_seq;
  40         PyObject *result = PySequence_GetItem(seq, it->it_index++);
  41
  42         if (result == NULL && PyErr_ExceptionMatches(PyExc_IndexError))
  43                 PyErr_SetObject(PyExc_StopIteration, Py_None);
  44         return result;
  45 }
  46
  47 static PyObject *
  48 iter_getiter(PyObject *it)
  49 {
  50         Py_INCREF(it);
  51         return it;
  52 }
  53
  54 static PyObject *
  55 iter_iternext(PyObject *iterator)
  56 {
  57         seqiterobject *it;
  58         PyObject *seq;
  59
  60         assert(PySeqIter_Check(iterator));
  61         it = (seqiterobject *)iterator;
  62         seq = it->it_seq;
  63
  64         if (PyList_Check(seq)) {
  65                 PyObject *item;
  66                 if (it->it_index >= PyList_GET_SIZE(seq)) {
  67                         return NULL;
  68                 }
  69                 item = PyList_GET_ITEM(seq, it->it_index);
  70                 it->it_index++;
  71                 Py_INCREF(item);
  72                 return item;
  73         }
  74         else {
  75                 PyObject *result = PySequence_GetItem(seq, it->it_index++);
  76                 if (result != NULL) {
  77                         return result;
  78                 }
  79                 if (PyErr_ExceptionMatches(PyExc_IndexError) ||
  80                         PyErr_ExceptionMatches(PyExc_StopIteration)) {
  81                         PyErr_Clear();
  82                         return NULL;
  83                 }
  84                 else {
  85                         return NULL;
  86                 }
  87         }
  88 }
  89
  90 static PyMethodDef iter_methods[] = {
  91         {"next",        (PyCFunction)iter_next, METH_NOARGS,
  92          "it.next() -- get the next value, or raise StopIteration"},
  93         {NULL,          NULL}           /* sentinel */
  94 };
  95
  96 PyTypeObject PySeqIter_Type = {
  97         PyObject_HEAD_INIT(&PyType_Type)
  98         0,                                      /* ob_size */
  99         "iterator",                             /* tp_name */
 100         sizeof(seqiterobject),                  /* tp_basicsize */
 101         0,                                      /* tp_itemsize */
 102         /* methods */
 103         (destructor)iter_dealloc,               /* tp_dealloc */
 104         0,                                      /* tp_print */
 105         0,                                      /* tp_getattr */
 106         0,                                      /* tp_setattr */
 107         0,                                      /* tp_compare */
 108         0,                                      /* tp_repr */
 109         0,                                      /* tp_as_number */
 110         0,                                      /* tp_as_sequence */
 111         0,                                      /* tp_as_mapping */
 112         0,                                      /* tp_hash */
 113         0,                                      /* tp_call */
 114         0,                                      /* tp_str */
 115         PyObject_GenericGetAttr,                /* tp_getattro */
 116         0,                                      /* tp_setattro */
 117         0,                                      /* tp_as_buffer */
 118         Py_TPFLAGS_DEFAULT,                     /* tp_flags */
 119         0,                                      /* tp_doc */
 120         (traverseproc)iter_traverse,            /* tp_traverse */
 121         0,                                      /* tp_clear */
 122         0,                                      /* tp_richcompare */
 123         0,                                      /* tp_weaklistoffset */
 124         (getiterfunc)iter_getiter,              /* tp_iter */
 125         (iternextfunc)iter_iternext,            /* tp_iternext */
 126         iter_methods,                           /* tp_methods */
 127         0,                                      /* tp_members */
 128         0,                                      /* tp_getset */
 129         0,                                      /* tp_base */
 130         0,                                      /* tp_dict */
 131         0,                                      /* tp_descr_get */
 132         0,                                      /* tp_descr_set */
 133 };
 134
 135 /* -------------------------------------- */
 136
 137 typedef struct {
 138         PyObject_HEAD
 139         PyObject *it_callable;
 140         PyObject *it_sentinel;
 141 } calliterobject;
 142
 143 PyObject *
 144 PyCallIter_New(PyObject *callable, PyObject *sentinel)
 145 {
 146         calliterobject *it;
 147         it = PyObject_NEW(calliterobject, &PyCallIter_Type);
 148         if (it == NULL)
 149                 return NULL;
 150         Py_INCREF(callable);
 151         it->it_callable = callable;
 152         Py_INCREF(sentinel);
 153         it->it_sentinel = sentinel;
 154         return (PyObject *)it;
 155 }
 156 static void
 157 calliter_dealloc(calliterobject *it)
 158 {
 159         Py_DECREF(it->it_callable);
 160         Py_DECREF(it->it_sentinel);
 161         PyObject_DEL(it);
 162 }
 163
 164 static int
 165 calliter_traverse(calliterobject *it, visitproc visit, void *arg)
 166 {
 167         int err;
 168         if ((err = visit(it->it_callable, arg)))
 169                 return err;
 170         if ((err = visit(it->it_sentinel, arg)))
 171                 return err;
 172         return 0;
 173 }
 174
 175 static PyObject *
 176 calliter_next(calliterobject *it, PyObject *args)
 177 {
 178         PyObject *result = PyObject_CallObject(it->it_callable, NULL);
 179         if (result != NULL) {
 180                 if (PyObject_RichCompareBool(result, it->it_sentinel, Py_EQ)) {
 181                         PyErr_SetObject(PyExc_StopIteration, Py_None);
 182                         Py_DECREF(result);
 183                         result = NULL;
 184                 }
 185         }
 186         return result;
 187 }
 188
 189 static PyMethodDef calliter_methods[] = {
 190         {"next",        (PyCFunction)calliter_next,     METH_VARARGS,
 191          "it.next() -- get the next value, or raise StopIteration"},
 192         {NULL,          NULL}           /* sentinel */
 193 };
 194
 195 static PyObject *
 196 calliter_iternext(calliterobject *it)
 197 {
 198         PyObject *result = PyObject_CallObject(it->it_callable, NULL);
 199         if (result != NULL) {
 200                 if (PyObject_RichCompareBool(result, it->it_sentinel, Py_EQ)) {
 201                         Py_DECREF(result);
 202                         result = NULL;
 203                 }
 204         }
 205         else if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
 206                 PyErr_Clear();
 207         }
 208         return result;
 209 }
 210
 211 PyTypeObject PyCallIter_Type = {
 212         PyObject_HEAD_INIT(&PyType_Type)
 213         0,                                      /* ob_size */
 214         "callable-iterator",                    /* tp_name */
 215         sizeof(calliterobject),                 /* tp_basicsize */
 216         0,                                      /* tp_itemsize */
 217         /* methods */
 218         (destructor)calliter_dealloc,           /* tp_dealloc */
 219         0,                                      /* tp_print */
 220         0,                                      /* tp_getattr */
 221         0,                                      /* tp_setattr */
 222         0,                                      /* tp_compare */
 223         0,                                      /* tp_repr */
 224         0,                                      /* tp_as_number */
 225         0,                                      /* tp_as_sequence */
 226         0,                                      /* tp_as_mapping */
 227         0,                                      /* tp_hash */
 228         0,                                      /* tp_call */
 229         0,                                      /* tp_str */
 230         PyObject_GenericGetAttr,                /* tp_getattro */
 231         0,                                      /* tp_setattro */
 232         0,                                      /* tp_as_buffer */
 233         Py_TPFLAGS_DEFAULT,                     /* tp_flags */
 234         0,                                      /* tp_doc */
 235         (traverseproc)calliter_traverse,        /* tp_traverse */
 236         0,                                      /* tp_clear */
 237         0,                                      /* tp_richcompare */
 238         0,                                      /* tp_weaklistoffset */
 239         (getiterfunc)iter_getiter,              /* tp_iter */
 240         (iternextfunc)calliter_iternext,        /* tp_iternext */
 241         calliter_methods,                       /* tp_methods */
 242         0,                                      /* tp_members */
 243         0,                                      /* tp_getset */
 244         0,                                      /* tp_base */
 245         0,                                      /* tp_dict */
 246         0,                                      /* tp_descr_get */
 247         0,                                      /* tp_descr_set */
 248 };